Heater Cores?

[Wilfred of Ivanhoe]

So, I meant to post this question some time ago, but it never happened. This has happened to me a few times over the years in my 69, and it happened again this winter.

1. I start up the truck.
2. I give it a little gas while still in park. (Nothing crazy or . RPMS never got that high)
3. Unmistakable green coolant begins to pour out from the passenger's side of my dash.
4. Upon inspection, it has been a blown/failed heater core every time.

Why does this happen? Is there an issue with these heater cores? Have I just gotten lemons, or is it just the operator? I have replaced the and seen failure with both new and old replacement heater cores. I am .

[jzjames]

When I recently installed my new heater core ($25 @ Oreilleys) I was real careful not to stress the tubes coming off it. Got it placed in and hooked up, no problems yet - knock on wood.
How many have failed on you? Doesn't sound right.

[colnago]

Are you sure it's the core itself, and not one of the lines coming in? I replaced mine with a new one from one of the auto stores, and never had a problem. I also had to replace the on/off ballcock, because this had also rusted out over the years. The biggest issue was that the copper tubes were placed in different locations from the original, so it was a pain to get it placed in the bracket. But since then, no problems.

Joseph

[69Ford]

Make sure the coolant lines are long enough and have enough wiggle room. If they don't engine tork may be pulling on the inlets of the heater core causing it to fail. I have seen this happen on some car's.

[Wilfred of Ivanhoe]

The coolant hoses are not short. If anything I leave a little extra in them in case the ends need trimmed in the future.

I know the failure was not at the inlet/outlet. It was pretty obvious that the failure was in the core's tubes/fins.

The first time this happened, I just assumed that my core was the original (i think it actually was) and that the years had taken their toll. I also had this happen to a new (O'Reilly's) core. I think I had one or two I had from parts trucks that failed.

I have also replaced the on/off ballcock once due to rust, but this seemed unrelated to the core issue.

[Lone Ranger]

Must just be a defect. I did one a few years back with a cheapo and it still works great. If you replace it again and it leaks again you might have to rethink the defect theory though.